Department of Gastroenterology and Hepatology, Amsterdam UMC, location VU Medical Center, AGEM Research Institute, Amsterdam, the Netherlands; Department of Immunology, Leiden University Medical Center, Leiden, the Netherlands. Department of Immunology, Leiden University Medical Center, Leiden, the Netherlands. Department of Gastroenterology and Hepatology, Amsterdam UMC, location VU Medical Center, AGEM Research Institute, Amsterdam, the Netherlands. Electronic address: g.bouma@amsterdamumc.nl.